This invention relates to a novel network architecture and more particularly to a multidimensional ring network.
Networks, whether they are circuit switched or packet switched, face a common set of problems. One problem is input congestion. This happens when too much traffic is directed to the network inputs. Another problem is internal congestion. This happens when there is insufficient throughput bandwidth to handle the routing of packets or other information within the network. Another problem is output congestion. This happens when too much traffic is directed towards the same network output. Another problem is limited fault tolerance. This happens when a section of the network fails preventing the information from being routed to its intended destination. When a failure is detected, information is typically rerouted along an alternative network path. But internal network congestion is often created when more information is routed through the alternative path. This prevents or substantially delays the information from reaching a target destination.
To resolve these congestion problems, processing nodes are added to the network to increase the input, internal and output capacity. Additional or tandem processing nodes can also be used as standby nodes in case of network failures. Several problems arise from increasing the number of nodes, e.g., scaling a network. The complexity of wiring and interface circuitry substantially increases as the number of nodes in the network increases. Latency also increases as additional nodes are added to the network. This increase in latency is caused by the additional hops required for the information to travel between the additional nodes to get from a network input to a network output.
U.S. Pat. No. 5,841,775 issued Nov. 24, 1998 to Huang describes a switching fabric of routers used to implement a scalable switching network. The problem with this switching fabric architecture is that it uses point-to-point interconnections. When additional routers are added to the network, either the number of routers in each row is increased or another row of routers is added to the switching fabric. If additional routers are added to each row, the wiring and interface complexity between the routers in each row is substantially increased. Each additional row added to the switching fabric adds additional hops to the network that increases network latency. Thus, the switching fabric architecture described in Huang has only limited scalability.
Accordingly, a need remains for a scalable network architecture that does not significantly increase latency or significantly increase wiring complexity.
A multidimensional ring network includes a plurality of network processing devices that are connected together with a plurality of individual ring networks. Packets are sent between any two network processing devices on the same ring network. Intermediate network processing devices located on that same ring, between the sending and receiving network processing devices, do not add additional hops to the packet transfer.
The intermediate processing devices, between the sending and receiving devices, simply pass the packets through to the next processing device on that ring. The packets are passed through to the destination processing device without the intermediate network processing devices having to read or process the packet headers. This allows the number of network processing devices on the individual ring networks and the number of individual ring networks in the multidimensional ring network to be increased without adding additional hops, and the associated latency, between the network processing devices.
The multidimensional ring architecture in one embodiment is arranged into a three-dimensional cube having X, Y and Z axes. The individual ring networks in the architecture interconnect the network processing devices logically aligned along the same rows and columns in the same planes of the cube. The same associated rows and columns in each of the different planes of the cube are then interconnected with other ring networks. One or more of the ring networks can also interconnect nodes that are logically arranged along a diagonally-extending line within the same plane or a diagonal line that extends through the different planes.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention which proceeds with reference to the accompanying drawings.